docs: def mobile_template(template):
      """
      Mark a function as mobile-ready and pass a mobile template if MOBILE.
  
      For example::
  
          @mobile_template('a/{mobile/}b.html')
          def view(template=None):
              ...
  
  
      if ``request.MOBILE=True`` the template will be `a/mobile/b.html`.
      if ``request.MOBILE=False`` the template will be `a/b.html`.
  
      This function is useful if the mobile view uses the same context but a
      different template.
  
      """
      def decorator(f):
          @functools.wraps(f)
          def wrapper(*args, **kwargs):
              ctx = stack.top
              if ctx is not None and hasattr(ctx, 'request'):
                  request = ctx.request
                  is_mobile = getattr(request, 'MOBILE', None)
                  kwargs['template'] = re.sub(r'{(.+?)}',
                                              r'\1' if is_mobile else '',
                                              template)
              return f(*args, **kwargs)
          return wrapper
      return decorator